Process of coating ferric articles with a metallic protective



Patented Dec. 30, 1924.

UNITED STATES PATENT OFFICE.

GEORGE K. THOMPSON, on SUMMIT, AND, JOSEPH ECKERT, .13., 0F MAURER, NEW JERSEY, assronons To HOYT METAL COMPANY, OF sT. LOUIS, MIssoUnI, A con- PORATION OF MISSOURI.

PROCESS OF COATING FER/RIC ARTICLES WITH A. METALLIC PROTECTIVE.

No Drawing.

To all whom it may concern:

Be it known that we, GEORGE K. THOMP- SON and JOSEPH ECKERT, J r., citizens of the United States of America, residents of Summit, in the county of Union, State of New Jersey, and of Maurer, in the county of Middlesex, State of New Jersey, respectively, have invented certain new and useful Improvements in Processes of Coating Ferric Articles with a Metallic Protective, of which the following is a full, clear, and exact description.

This invention relates to improvements in processes of coating ferric articles with a metallic protective whereby said articles are rendered impermeable to rust and corrosion, and has for its object the production of a process whereby a smooth, even coating may be deposited on the treated article, the junction between said ferric article and said protective coating being maintained chemically pure and mechanically intimate.

The first step of the process is the thorough cleaning of the article to be coated, preferably by immersing same in a solution of either muriatic or sulphuric acid whereby all rust, dirt and other impurities are removed from the surface of the article and from the pores and cavities therein, said so lution being formed by mixing water and varying percentages of acid. While the solutions mentioned above constitute very etficient pickling means, still we do not limit ourselves to these methods as any means which will thoroughly clean the article to be coated may be employed.

After the article has been thoroughly cleaned in the manner set forth, said article is passed through a bath containing zinc chloride as a flux whereby the article is prepared for the reception of the protective coating.

After the article being treated has been passed through the zinc chloride it is immersed in a bath of molten protective coating material of either lead or an alloy, the constituents of which alloy are antimony and lead, the antimony content thereof varying from of 1 per cent to 16 per cent, and

Application filed June 12, 1922. SeriaI No. 567,822.

because the fluxing material has preserved the surface of the article free from oxide, :1 unlon 1s formed between said article and said protective coating which is chemically pure and mechanically intimate.

Immediately upon being withdrawn from the molten protective coating material. the article treated is immersed in a bath of molten 'parafiin or stearin, or other waxy substance, to which may be added varying proportions of zinc chloride or tin chloride 1n percentages of zinc or tin chlorides from a trace to 26 percent. This treatment of the artlcle to a bath of paraffin or stearin results in a smooth, even coating of the coating material on the metal.

The lmmersion of the lead coated ferric article in the bath of waxy material for a time sufficiently long to produce the smooth even coating, appears to result in a tempermg operatlon and the hardened coating materlal firmly adheres to the ferric material.

We claim:

1 The process of coating ferric articles which comprises applying a flux to the surfaces of the articles, immersing said articles in a bath containing molten lead as a ma or ingredient, withdrawing said article from said bath, and then immersing said articles in a bath of molten waxy material.

2 The process of coating ferric articles which comprises applying a fiux to the surfaces of the articles, immersing said articles in a bath containing molten lead as a major in redient, withdrawing said articles fromsaid bath, and then immersing said articles in a bath of molten parafiin.

3 The process of coating ferric articles WlllCh comprises applying a flux to the sur faces of the articles, immersing said articles in a bath containing molten lead as a major ingredient, withdrawing said articles from said bath, and then immersing said articles in a bath of molten waxy material containing a chloride.

In testimony that we claim the foregoing we hereunto aflix our signatures.

GEORGE K. THOMPSON. JOSEPH EOKERT, JR. 

